Science

Engineering materials have the following Key Characteristics: Common Examples: Alumina ($Al_2O_3$), Silicon Carbide (SiC), Zirconia ($ZrO_2$), and common window glass (silica-based). 3. Polymers (Plastics) Polymers are long-chain organic molecules (based on carbon and hydrogen) where repeating molecular units (monomers) are joined together by covalent bonds. Key Characteristics: Classification Subgroups: Common Examples: Polyethylene (PE), Polypropylene (PP), Nylon, Bakelite, Epoxy resins. 4. Composites Composites are materials made from two or more constituent materials with significantly different physical or chemical properties that remain separate and distinct on a macroscopic scale within the finished structure. They are designed to achieve better properties than the individual components alone. Key Characteristics: Structure: Common Examples: Fiberglass (Glass fibers in a polymer matrix), Carbon Fiber Reinforced Polymer (CFRP), Reinforced Concrete, and advanced composites used in aircraft.